Robert Harris has been announced as the winner of a £25,000 historical fiction prize for his novel An Officer And A Spy.

The best-selling British author, whose previous titles include Fatherland and Pompeii, is the recipient of this year's Walter Scott Prize.

Harris was presented with the award this evening at the Borders Book Festival in Melrose in the Scottish Borders.

An Officer And A Spy recreates one of history's most infamous miscarriages of justice - the conviction of Jewish officer Alfred Dreyfus for treason in Paris in 1895.

Judges described it as "a masterwork written by a story-teller at the pinnacle of his powers".

The panel, which included broadcaster and author Kirsty Wark, said: "The book is set at the end of the 19th century but its themes have resonated ever since. Cover-ups, anti-semitism and a suspicion of the other, codes and leaks, and the mission of a single individual to force a government to right an injustice - all of these have modern parallels.

"From a shortlist of extraordinary quality a clear winner emerged and the judges were unanimous in their choice. Nevertheless we congratulate all the shortlisted authors on their books and thank them for transporting us to such an enthralling diversity of times and places."

Now in its fifth year, the Walter Scott Prize honours Scott's achievements as one of the world's most influential novelists.

To qualify, novels must be set at least 60 years ago, be written in English, and have been published in the preceding year.

The shortlist included two other literary prize holders - the Man Booker Prize-winning The Luminaries by Eleanor Catton and Kate Atkinson's Life After Life which took the Costa Prize.